关键词: 涡流检测, 焊缝缺陷, 经验模态分解, 主成分分析, 支持向量机

Abstract: An effective eddy current testing method was presented to identify the defects of narrow lap joints. Firstly, the characteristic parameters of eddy current signals were extracted by EMD. Then, based on PCA, the characteristic parameters were reduced, the redundant informations were removed, and the main element characteristics of the welds were obtained. In the end, the main element features were used as the inputs of SVM to construct the multi-classifier, and the eddy current measurement signals of the narrow lap were identified. The results show that this method has high accuracy and low complexity. It may effectively identify different defects of weld seams, and has good engineering application values.

Key words: eddy current testing, weld defect, empirical mode decomposition(EMD), principal component analysis(PCA), support vector machine(SVM)